Apparatus for controlling the level of subsurface water

ABSTRACT

Float-actuated valve means connected between a pump and the upper end of a pipe sunk in the ground, the valve means functioning to control the flow of water to the pump in accordance with the rate of flow of water drawn through the pipe. An air passageway bypasses the valve means to provide a reduced pressure condition in the pipe when the valve means is closed.

United States Patent [1 1 Moore 1 1 APPARATUS FOR CONTROLLING THE LEVEL OF SUBSURFACE WATER [75] Inventor: Edward J. Moore, Morris Township,

[73] Assignee: Moretrench American Corporation,

Rockaway, NJ.

[22] Filed: June 10, 1974 [21] Appl. No.: 477,608

[52] US. Cl. 417/279 [51] Int. Cl. .1 F04b 49/04 [58] Field of Search 417/279, 211.5

[56] References Cited UNITED STATES PATENTS 1,616,134 2/1927 MacMahon 417/279 X June 10, 1975 Hundley 417/279 X Purtell 417/279 X Primary ExaminerWi11iam L. Freeh Assistant ExaminerLeonard Smith Attorney, Agent, or Firm-Rudo1ph .1. Jurick {57] ABSTRACT Float-actuated valve means connected between a pump and the upper end of a pipe sunk in the ground, the valve means functioning to control the flow of water to the pump in accordance with the rate of flow of water drawn through the pipe. An air passageway bypasses the valve means to provide a reduced pressure condition in the pipe when the valve means is closed.

6 Claims, 4 Drawing Figures APPARATUS FOR CONTROLLING THE LEVEL OF SUBSURFACE WATER BACKGROUND OF THE INVENTION Systems for removing water from the ground include a series of well points sunk into the ground at spaced intervals and a pumping unit for drawing water out of the ground through the well points. One problem common to prior well point systems is caused by the fact that air or other gases enter into the well points when the level of the water is lowered to the intake ends of the well points. When this occurs at a plurality of well points, the excess air drawn into the pump causes the pump to lose the degree of vacuum required to exhaust the water in all of the other well points. Heretofore, it has been necessary for an attendant to adjust manually operable valves associated with each of the well points in order to re-balance the system and assure a flow of water through each well point upon a subsequent increase in the ground water level. Generally, a well point system is operated 24 hours per day and the requirement for continuous supervision by attendants adds to the cost of operation.

Apparatus made in accordance with this invention automatically adjusts the flow of water to the pump from each well point in accordance with the amount of air being drawn into the particular well point. At the same time, the apparatus maintains a reduced pressure in the well point, whereby the flow of water to the pump is re-established when the air drawn into the well point decreases.

An object of this invention is the provision of improved apparatus for controlling the level of ground water.

An object of this invention is the provision of a floatactuated valve connected between a pump and a well point, which valve controls the flow of water to the pump in accordance with the flow rate of water drawn into the well point.

An object of this invention is the provision of an arrangement for separating air out of a stream of water flowing between a well point and a pump, which arrangement includes float-actuated valve controlling the flow of water to the pump and means for maintaining a reduced pressure in the well point when the valve is closed.

The above-stated and other objects and advantages of the invention will become apparent from the following description when taken with the accompanying drawings. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as defining the scope or limits of the invention, reference being had for the latter purpose to the claims appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings wherein like reference characters denote like parts in the several views:

FIG. 1 is an elevational view of apparatus made in accordance with one embodiment of this invention;

FIG. 2 is vertical cross-sectional view of such apparatus drawn to an enlarged scale;

FIG. 3 is a cross-sectional view taken along the line Ill [ll of FIG. 2', and

FIG. 4 is similar to FIG. 2 and showing another embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENT Reference is made to FIG. 1 showing a well point water removal system embodying this invention. The well point comprises a pipe 10 sunk into the ground I1 and having its upper end connected to a cylindrical tank 12. An inlet screen 13 is provided at the lower end of the pipe. The lower end of the tank 12 is connected to a header pipe 14 by a pipe 15 having a diamenter approximately equal to that of the well point pipe 10. When the pump 16 is in operation, water is drawn upwardly through the pipe 10, downwardly through the tank 12, and is discharged to a remote point from an outlet pipe 17. In this embodiment of the invention, a bleeder tube 18, provided with a manually adjustable valve 19, is connected between the tank 12 and the header pipe 14 for purposes which will be described below. As is well known, such a well point system can be used to dry the ground to a desired depth to facilitate ground excavation, or to draw water from the ground for domestic or industrial use. Generally, a plurality of well points are sunk into the ground at spaced intervals, all well points being connected to the header pipe 14, and the pump has a capacity to maintain a full flow of water through all of the well points. As the ground water level is reduced at a particular well point, it eventually falls below the top of the screen 13, as indicated by water-level lines identified by arrows a. When this occurs, air begins to be drawn into the pipe 10. As the water level is further decreased, the ratio of air to water increases and, eventually, a considerable amount of air is being drawn through the well point. When this condition occurs at several well points, the pump can no longer maintain the degree of vacuum required to exhaust the water from the remaining well points at which the water level is above the screens. This problem is overcome by the arrangement now to be described.

Referring to FIG. 2, the cylindrical tank 12 is closed except for the connections made to the well point pipe 10, the header pipe 14 and the bleeder tube 18. A circular baffle plate 2] is suspended from the top of the tank by a plurality of radially spaced struts 22. Dis posed within the tank is a float chamber 23 having a plurality of openings 24 formed in the bottom 25 thereof, see also FIG. 3. The chamber 23, having a normally open top, is secured to the inner surface of the top of the tank 12. A float 26 is disposed within the chamber 23, said float having secured thereto a flexible member 27 made of rubber and spanning all of the openings 24. Thus, when the float is in the illustrated raised position all of the openings 24 are fully open permitting a maximum flow of water out of the chamber 23 into the header pipe 14. When the chamber 23 is empty all of the openings are closed by the member 27.

The valve 19, and all similar valves associated with the other well points of the system, are adjusted so that the pump develops a reduced-pressure condition in all of the bleeder tubes upon start-up of the system. By creating a vacuum condition in the bleeder tube 18 and the float chamber 23, water rises in the well point pipe 10 and flows into the float chamber. The baffle plate 21 prevents direct impingement of the water on the float, thereby stabilizing float operation. At the same time, air is separated from the incoming water stream and accumulates at the top of the chamber 23. The air is drawn off continuously through the bleeder tube l8. As the water in the chamber 23 accumulates, the float begins to rise and the flexible member 27 uncovers some of the openings 24, specifically those openings remote from the float axis, and water now flows into the header pipe 14 and to the pump. The buoyancy of the float is sufficient to raise the peripheral portion of the flexible member from the underlying openings regardless of the pull exerted on the flexible member by the vacuum condition initially prevailing in the header pipe 14. If the rate of water flow into the chamber 23 exceeds the rate at which water is drawn out of the chamber. the float continues to rise. whereby the flexible member is peeled from the bottom of the float chamber to uncover more and more of the openings. When all of the openings are uncovered, the rate at which water flows into the header pipe 14 is equal to the rate at which water is discharged into the float chamber from the pipe 10.

When the ground water level has been lowered to the top of the screen 13, see FIG. 1, air enters into the pipe and is drawn into the float chamber. The float now settles and the flexible member 27 closes the centrally located openings 24. More and more of the openings are closed as the ratio of air to water in the pipe 10 increases. The air is separated from the water at the baffle 21 and accumulates at the top of the chamber 23. When all of the openings 24 are closed, water pumping from the pipe 10 stops. The air is removed through the bleeder tube 18, thereby creating a reduced pressure condition in the float chamber and the pipe 10 so that water will again be drawn through the pipe when the ground water rises above the screen 13. The bleeder tube has a relatively small diameter, of the order of one-eighth inch, and the valve 19 is adjusted so that the rate of air flow through the tube has no appreciable effect on the ability of the pump to maintain the required degree of vacuum in the entire well point system.

Reference now is made to FIG. 4 showing another embodiment of the invention. In this arrangement. the float 26 has a dome shaped top against which the water stream from the pipe 10 impinges. The dome shaped top minimizes disturbance of the float action by the incoming water stream. A small opening 30 is provided in the wall of the float chamber 23, which opening replaces the bleeder tube 18 and valve 19 shown in FIG. 2. Air which accummulates at the top of the float chamber is drawn off through the opening 30 and the passageway formed between the float chamber and the outer tank 12.

From the above description it is apparent that the ap- 4 paratus functions automatically to maintain unity between the rate of flow of water drawn through the well point and the rate of flow of water passing into a header pipe while, at the same time, causing the water to commence flowing through the well point as the ground water lcvei rises above the well point screen.

Having now described the invention, what I desire to protect by letters patent is set forth in the following claims.

I claim:

1. Apparatus for controlling the level of subsurface water and comprising,

a. a float chamber having a plurality of openings formed in the bottom wall thereof,

b. a float in said chamber,

c. a flexible member secured to the bottom of the float and spanning the said openings,

d. a header pipe communicating with the said openings,

e. a pump connected to said header pipe for producing sub-atmospheric pressure within said header pipe,

f. a vertical pipe sunk in the ground and connected to said float chamber, said pipe having an inlet opening at the lower end portion thereof, and

g. means forming an air passageway between the header pipe and the top of the float chamber.

2. Apparatus as recited in claim 1, wherein the said means forming an air passageway is a bleeder tube disposed externally of the float chamber.

3. Apparatus as recited in claim 1, wherein the said vertical pipe is connected to the top of the float chamber, and including baffle means positioned in the float chamber and spaced from the top thereof, said baffle means directing water flow from the vertical pipe toward the inner wall of the float chamber.

4. Apparatus as recited in claim 1, including an outer tank, said tank having a side wall spaced from a side wall of the float chamber and a bottom wall spaced from the bottom wall of the float chamber.

5. Apparatus as recited in claim 4, wherein the said means forming an air passageway includes an opening formed in the said side wall of the float chamber and the space between the side walls and bottom walls of the tank and float chamber.

6. Apparatus as recited in claim 1, wherein the said float has a domeshaped top. 

1. Apparatus for controlling the level of subsurface water and comprising, a. a float chamber having a plurality of openings formed in the bottom wall thereof, b. a float in said chamber, c. a flexible member secured to the bottom of the float and spanning the said openings, d. a header pipe communicating with the said openings, e. a pump connected to said header pipe for producing subatmospheric pressure within said header pipe, f. a vertical pipe sunk in the ground and connected to said float chamber, said pipe having an inlet opening at the lower end portion thereof, and g. means forming an air passageway between the header pipe and the top of the float chamber.
 2. Apparatus as recited in claim 1, wherein the said means forming an air passageway is a bleeder tube disposed externally of the float chamber.
 3. Apparatus as recited in claim 1, wherein the said vertical pipe is connected to the top of the float chamber, and including baffle means positioned in the float chamber and spaced from the top thereof, said baffle means directing water flow from the vertical pipe toward the inner wall of the float chamber.
 4. Apparatus as recited in claim 1, including an outer tank, said tank having a side wall spaced from a side wall of the float chamber and a bottom wall spaced from the bottom wall of the float chamber.
 5. Apparatus as recited in claim 4, wherein the said means forming an air passageway includes an opening formed in the said side wall of the float chamber and the space between the side walls and bottom walls of the tank and float chamber.
 6. Apparatus as recited in claim 1, wherein the said float has a dome-shaped top. 